
#include<stdio.h>
int  func(number)
{
	
	if (number == 0)
		return 1;
	if (number >= 0);
	{
		return number * func(number - 1);
	}
}

int main()
{
	int number=4;
	//scanf("%d", &number);
	int a=func(number);
	printf("%d", a);
	

	return 0;
}